In the film versions Gandalf ends Sauramons power by breaking his staff but would not like wise Gandalf magical/supernatural power be ended by the Witch king ? And only in the epilogue of the third film is Gadalf hinted at having the third elf ring Thanks

the staves are symbols of power and also a tool through which the istari channel some of their power when necessary. (Perhaps they have a turbo-boost effect?)

Breaking Saruman's staff is certainly a symbolic gesture. We can only hypothesise about the practical effects of losing a staff: As you say, Gandalf retained his power when the Witch-king shattered his staff, so maybe Saruman either did not experience a loss of actual power or he had been relying on his staff too much and had become weakened by its loss. We'll never know for sure.

"Ah, how ironic, the addictive qualities of Sauronís master weapon led to its own destruction. Which just goes to show, kids - if you want two small and noble souls to succeed on a mission of dire importance... send an evil-minded beggar with them too." - Gandalf's Diaries, final par, by Ufthak.

The novel makes it clear that the staffs are necessary for the wizards to do their magic. Gandalf uses his, whether he's lighting a piece of wood on fire or making the outlines of the door appear at Moria or breaking the Bridge under the Balrog. When he breaks Saruman's staff, it's clearly a major event, and he later says that Saruman is incapable of anything more than making small, mean trouble.

But the film doesn't stick to that premise. I agree, the moment when the Witch King knocks Gandalf off his horse and breaks his staff is not consistent with the rest of the film. A lot of people have commented here on the Boards about how they don't like that scene and don't think it makes sense. I agree!

But the way that I I like to look at it, is that Gandalf actually is more powerful than the witch-king, and that the breaking of his staff was just a result of Gandalf's fear of not being able to overcome his foe.

Not entirely sure if this is what PJ and company were going for or not, but that's the only way that it makes sense to me.

On the one hand, Gandalf can come galloping out from the city and zap the Nazgul so that they leave, but he can't even try to put up a fight against the Witch King? Sort of like the inevitable question from people who haven't read the book: why doesn't Gandalf ride an Eagle, or send Frodo on one, to Mount Doom. There are some definite gaps in the motivation of such moments.

or how I like to think of it is that when the Witch-King breaks Gandalf's staff, it happens because Gandalf is absolutely exhausted - he looks so haggard and old during the battle - but because he is Gandalf the White, he ultimately doesn't need the staff, as he has transcended beyond the need to channel his power through 'worldly' objects.

...although I suspect you put more thought into that scene than the filmmakers did. In myth and folklore the wand or staff is like an antenna; it focuses the power without being the source. As for the WK defeating GTW, I suppose they felt it would ramp up the tension but it raises more questions than it answers.

they wanted to reinforce the idea that the WK was a serious threat and that no man could kill him, so when Eowyn kills him, it's even more impactful. Well, that's what I think when I try to look at it from a filmmaking point of view.